In recent years, it has become clear that, in autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematoses, Guillain-Barre syndrome, and idiopathic thrombocytopenic purpura, or in diseases such as glomerular nephritis, rejection of transplanted organs, tumor, and infectious disease, immunoglobulins and/or immunoglobulin complexes present in the blood have a close relationship with the cause or progress of diseases and/or phenomena.
Under the above-mentioned circumstance, several adsorbing and removing materials have been utilized in the hope of preventing the progress of the above-mentioned diseases, relieving the conditions, and furthermore promoting healing by specifically adsorbing and removing immunoglobulins and/or immunoglobulin complexes from the body fluid such as the blood and the plasma. For example, an immune adsorbent (Japanese Laid-open Publication No. 62-242628) in which protein A capable of binding to immunoglobulins is immobilized onto a silica matrix is known as an adsorbent which is highly specific to immunoglobulin G and immunoglobulin complexes thereof. Furthermore, an adsorbent (Japanese Laid-open Publication No. 57-122875) for immunoglobulins and/or immunoglobulin complexes in which a hydrophobic compound is immobilized onto an insoluble carrier has already been clinically applied in Japan.
However, the adsorbent which has been used (e.g., the above-mentioned adsorbent for protein A) has disadvantages. Specifically, protein A, which is a functional group, is a heterogenous protein having a molecular weight of about 42,000 daltons derived from Staphylococcus aureus, so that when the adsorbent is used in contact with the body fluid, protein A is eluted and its antigenicity may cause side effects. Also there is a problem of stability during sterilization of the adsorbent, therefore sterilization method is limited. Additionally, storage stability is not sufficient after protein A is immobilized onto a silica matrix; and the like. Furthermore, the adsorbent for immunoglobulins and/or immune complexes thereof described in Japanese Laid-open Publication No. 57-122875 has the disadvantages of poor adsorbing characteristics such as adsorption specificity to a substance of interest and adsorbing capacity (I. Amano et al., "Blood purification therapy, 1st part", Japanese Journal of Clinical Medicine, Vol. 49, pp. 649-654 (1991 sup.). Accordingly, in terms of the safety, stability, adsorbing specificity, adsorbing capacity, and the like, the conventionally known adsorbent for adsorbing immunoglobulins and/or immunoglobulin complexes is not necessarily suitable for use in treating diseases caused by the presence of the above-mentioned pathogenic immunoglobulins and/or immunoglobulin complexes in the body fluid.